Texan77, nice try, but no biscuit for you. Rather than trying to make unsafe inferences from secondary data, why not look at what is actually happening and what is being planned for in China.
For ease I suggest you take a look here: https://en.wikipedia.org/wiki/Migration_in_China
The article refers to migrant workers - these are the engine of the move from (mostly) rural areas to urban areas. They remain migrants until they settle permanently, but settle they do. Even if not permanent settlers they require housing.
The concept of migrant workers as it applies in China is not what you likely associate with your experience - that's due to the Chinese system of Hukuo which ties people's access to social services to their place of birth. Meaning that a person who has lived in a new location for decades will still be considered a migrant, a person only temporarily in the urban area he and his family now live.
To save you the bother of reading, from the article:
in 2015 there were about 277.5 million migrant workers - about 1/3 of all employment. Estimates are that Chinese cities will face an influx of another 243 million migrants by 2025, taking the urban population up to nearly 1 billion people.
Think for a moment Texan77, if we divide 277 million by 10 years, the result is 28 million new people per year, between 2015 and 2025.
How many new cities does that suggest will be built?
How long does it take to build a city?
Now do you better grasp what is going on and the time scales?
Urbanisation in China: https://www.statista.com/statistics/270162/urbanization-in-china/
Texan77, the scale and numbers are unimaginable to most people - especially if you have never seen the situation - and I saw it many years ago and only for a brief time.
So, yes, homes, usually apartments, are being built and purchased speculatively, but it is not a bad bet. Those homes will fill up and, as I somewhat facetiously noted upthread - and to which you objected, after about 5 years. You see, development MUST be done ahead of time. Building according to the demand of the moment simply is not possible, so speculative purchase of apartments as investments form a kind of buffer.
Look at the proper numbers matey rather than making assumptions, or echoing the assumptions of others - it helps.
Worth noting that the Chinese government is now looking at ways to reduce the movement to the huge cities concentrated in the coastal regions. The next phase is likely to be developments in the western parts of the country and although English language articles talk about this being a return to keeping people in rural areas, it most certainly isn't. The commentators don't seem to have a grasp of the scale of the issue and what the policy discussions from the top mean in real terms.